THERE are 300 million people in the United States of America. There are millions of political activists, volunteers, organizers and would-be officeholders. There are hundreds of thousands of elected officials. Yet somehow, out of all this multitude, the Republican Party has been unable to find a candidate for the White House in 2012 who inspires anything but weary resignation from its voters.

What’s remarkable is how often this seems to happen. As weak as this year’s Republican field has proved, it’s not that much weaker than a number of recent presidential vintages, from the Democrats’ lineups in 1988 and 2004 to the Republican field in 1996. In presidential politics, the great talents (a Clinton, a Reagan) seem to be the exception; a march of Dole-Dukakis-Mondale mediocrity is closer to the rule.